三维锥束CT中几何参数的校正研究  

Calibration of Geometrical Parameters in 3D Cone-beam CT

作　　者：席东星[1] 张树生[1] 李悍[1] 

机构地区：[1]西北工业大学现代设计与集成制造技术教育部重点实验室,陕西西安710072

出　　处：《计算机仿真》2011年第1期253-256,共4页Computer Simulation

摘　　要：计算机断层成像技术在工业和医学中的应用,三维锥束CT(Computed Tomography)是显微CT和工业CT目前研究的热点。三维锥束CT系统一般采用FDK重建算法,算法要求锥束中心射线垂直于探测器且投影在探测器中心,然而由于系统机械精度的不足难满足要求,从而给重建结果带来伪影。为解决上述问题,提出了一种投影数据的校正方法:在重建前首先根据几何参数对每幅投影数据进行修正,修正完后再进行重建。实验结果证明:改进后能有效地改善几何参数误差引起的图像失真,对三维锥束CT扫描系统的几何校正具有重要意义。The research of 3D cone-beam CT is the hottest topic of micro-CT and industrial CT, and is the direc- tion of the development of medical CT. Confined by limited orientation precision due to mechanical errors, 3D conebeam CT system usually fails to meet the precondition that rotation center must accord with reconstruction center in widely adopted FDK algorithm, which arouses artifacts in reconstructed. This paper proposes a calibration method to correct the projection data before reconstruction. Experiments prove that the method can improve the image distortiot~ caused by inaccurate geometric parameter and well meet the requirement of calibration in 3D cone-beam CT system.

关 键 词：几何参数 几何校准 三维重建 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]